Justin Bieber, Cleveland dudes are MUCH bigger than you- you gotta watch OUT.

But hey, one warning too late. Ya see, Biebs got into an all-out street brawl with a guy much bigger than him Wednesday night in Cleveland, after some kind of exchange post-NBA finals.

Nobody knows how it exactly started, but Bieber was in Cleveland in the first place to watch fgame 3 of the NBA Finals, and was wearing a Cleveland Cavaliers shirt. So, it could be some post-game hate. Witnesses say Bieber was getting peppered with requests for photos, and we all know how much he’s not into that.

TMZ is circulating this video of Bieber, shot shortly after 11 PM, outside his hotel in downtown Cleveland. If you check it out, it shows Biebs face-to-face with the guy, who punched Justin’s head. Then Justin unleashed his own pop star fury by throwing another right into the guy’s face. And then..it was ON.

A couple bystanders tried to jump in, but the fight ends up spilling to the ground.